This invention relates generally to electric motors, and, more particularly, to a condenser fan motor for use in refrigeration systems.
Refrigerators typically include a compressor coupled to a condenser so that compressed refrigerant flows to the condenser. See, for example, U.S. Pat. No. 5,711,159. A condenser fan circulates air over a surface of the condenser to cool the compressed refrigerant and is powered by a condenser fan motor.
Condenser fan motors typically are four pole electric motors. Cost savings could be realized if two pole motors could be used. An important attribute of a condenser fan motor, however, is its ability to run in the presence of contaminants. Two pole motors can be vulnerable to contaminants, such as lint or hair, that become wrapped around the motor shaft and tend to migrate toward a front motor bearing. As the contaminates contact the motor bearing, oil is drawn from the bearing, which eventually can lead to motor failure. Also, the contaminants may bind the motor and prevent the output shaft from turning altogether.
Accordingly, it would be desirable to use more cost effective two pole motors for condenser fan applications while avoiding reliability concerns from contaminants reaching the front motor bearing.